Apparatus for low temperature gas compression



NOV. l, i949. G, E, HOCKENS 2,486,598

APPARATUS'FOR LOW TEMPERATURE GAS COMPBESSION 7 l JNVENTVOR.

Nov. l, 1949. l G. E. HocKENs 2,486,598

APPARATUS FOR LOW TEMPERATURE GAS COMPRESSION Filed Dec. 13, 1947 4 Sheets-Sheet 2 g5, 94 47 42; 67 fi 416 42 zo A29 I' -Tg v V INV/ENTOR. I

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NOV' l, 1949 G, E. HocKENs APPARATUS FOR LOW TEMPERATURE GAS COMPRESSION 4 Sheets-Sheet 3 F'led Dec. 15, 1947 INVENTOR. M

Nov. l, 1949.

` G. E. HOCKENS APPARATUS FOR LOW TEMPERATURE GAS COMPRESSION 4 Sheets-Sheet 4 Filed Dec. 13, 1947 #u 8; 5 a@ M f l 0 Patented Nov. l, 1949 APPARATUS FOR LOW TEMPERATURE GAS: COMPRES SION Gra-nt E. H0ckens,. East Aurora, Ni. Y., assignorL to The Wittemann Company,l I-nc.,.Buffalo,l-N..Y..

Application December 13, 1947; Serial No. 791,594!

4 Claims. 1.

This inventionrelates to improvements in gasA compressors. More particularly this invention relates to apparatus: for use in connection with the compression ci carbon dioxide formed d-.uring fermentation inthemanuiacture of certain types of beverages.

It is well known that' carbon dioxidee gas formed during the process oft'ermentation in the making or beverages. contains-` certain volatiles, such.` as esters, which impart desirable flavors and aromas to beveragessuchl asbeersvand ales when such gas is used in connection. with the: handling or carbonating of' the beverages, and it is also well known that` such volatiles or esters are readilyaltered when heated to temperatures' in the neighborhood of 100' degrees FL', so that the desirable flavors and aromas are destroyed. In order to efficiently'. store such. fermentation. gases. it is necessaryto compress them to high pressures or to liquefy them.. If ordinaryv gas' compressors are used: for this; purpose, the` gas; is raised?. to temperaturesv far in excess to,A those at.v which. the volatileswill be altered, and furthermore inordinary compressors.: lubricants'. such: as; commonly used to.- form an oili film betvizeen` the; piston and the cylinder Wall'wiliz become mixed With. thee fer'- mentati'on gaisY so as to render the same obiectionable for use in connection. with; the treatment or handling oi beverages7 since:Y even smelt quanti tiles, or oil' will adversely aiect, the taste and foamingr properties of'` the.v beverage., Water has been added to` the.i fermentation. gases: and. injected into the; compressors for cooling; the gases during compression, but. this method of compres sing such gases: has annmber oft'objfeotions, inclnclnig the diiicultyoffmairrtaining a: supply of the correctl amount of `ctrl'd'rvvater to the cornpressor and then. separating thevwater from the compressed gas;

One, of the objects: of: this: invention is to; provide an improved'. apparatus, for compressing fermemtation gas Withoutl altering4 the volatiles; which impart flavor and aroma to the gas:n Another object of thisl invention is; to provide: an apparatus oi: this: type in which the: gas be compressed while dry and1 withontz'the presenceoi waterV or. liquidl lubricant int the cormrrressorV in contact with the gas.. It. also an; object of this invention to provide. a compressor; the cylinder of which is enclosedi'n a. housingwhich; forms `the evaporator orarefrigerating system..

Another obiect of this invention. is to provide a compressor Withia housirig;surrou-nding thecylin'- der andv containing a. readily' volatile refrigerant and in which. passages for the fermentation. gas

(Cl. 230--212U leading to and from the cylinder are provided-jin which this gasv is; cooled' While passing to and' from the. compressor. A. further object; is to provide afmulti-stage compressor having its: housing` enr closed in an evaporatorl of: a4 refrigeratmg system and having passagesiwithin the enclosure' exposed to the action of said refrigerant through which the fermentation gas: passes before: compression, and between the compression stages. and by means of which refrigerant thecompressor. itself is: cooled: to such an extent.- thatthe fermentation gas at no. time israised to a temperaturefat which the'volatiles. therein, are altered.. A. furtherobject is' to provide a compressor having a piston ot improved construction which. has; a. removable head and onwhich piston rings of carbonorother com.- position. which doi not require lubrication may be used'. Other objects and advantages. of: this.: in.- verrtion will. appear from. the following; descrip,- tion and. claims..

In the. accompanying drawings:

Fig. i isa fragmentaryelevation, partly in sec'. tiem. of a compressor embodying this invention.

Fig. 2 is a transverse-i.. sectionalv planview thereof on line 2 2', Fig. 1.

Fig. 3f is: a. fragmentary centra-L sec-tional eleva'- tiorr thereof.

Figs. 4, 5 and 6 respectively arev sectional plan views thereof on lines 4 4, 5-5 and 6 6 respectively, Fig. 3.

Fig. '7 is a diagrammatic 4vievv showing my improved. apparatus embodying; this. invention.

Myr improved process may be carried out. by means; of. a gas` compressor of any suitable or desired type, such as rotaryv or reeiprocatory.. In the accompanying draw-ings I have shown, by Way oi example-, my invention. applied to-a reciprocating compressor having ay cylinder |10. within which a piston l I is mountedto reciprocate. Since compressors of thisl type arey well known, I, have not deemed it necessary here to. show the entire mechanism employed for imparting reciprocation to they piston. In Fig., 1 I have, however,y illus.- trated across head t2 mounted to reciprocate in guides i4 andA connected with a connecting rod or pitm-an l5, the lower end of which cooperates with a` crank shaft (not shown).

In; compressors of this type as heretofore constructed, a liquid lubricant such as Water or oil has been used to lubricate the piston rings. In order to avoid the use of any liquid lubricants, I have provided a piston which is constructed to b e used in connectionK with piston rings made of carbon or of a plastic. material capable `of .operating: without; such. liquid lubricants. For this. purpose the piston II is preferably constructed to receive a solid or one piece guide ring as hereinafter described.

The piston II consequently is preferably of hollow, substantially cylindrical form and has a removable head I8 which is rigidly secured thereto, for example by means of a piston rod or shaft I1 extending axially through the piston and having its upper end' threaded and engaging in a threaded hole in the head I8. The piston head ts tightly against the upper end of the piston I I and is held in axial alinement therewith in any suitable manner, for example by means of intertting annular parts as shown in Fig. 3, including a downwardly extending projection 20 fitting into a corresponding depression in the upper end of the piston, and the head is suitably held against rotation relatively to the piston, for example by means of a pin I9. The bottom of the piston head is provided at its periphery with a portion of reduced diameter ywhich together with the upper end of the piston forms a groove in which a guide ring 2I ts snugly. This guide ring is of solid or one piece construction, not being split or formed in segments, and is consequently fitted into the reduced lower portion of the piston head before the piston head is secured to the piston. The piston head may then be secured to the piston by means of the piston rod I1, the lower portion of which is also screw threaded and engages a correspondingly threaded flanged sleeve 22 which is secured to the lower end of the piston in any suitable manner, for example by means of bolts 23 extending through holes in the flange of the sleeve 22 and into threaded holes in the lower end of the piston. The piston rod or pin I1 is rst threaded into the threaded hole in the piston head and the head is then drawn tightly against the upper end of the piston by turning the sleeve 22 until sufficient tension is applied to the piston rod I1 to tightly draw the head I8 against the upper end of the piston. The portion of the piston rod below the nut 23 may be suitably secured in any desired manner to the cross head I2.

Additional piston rings are employed for forming a seal between the piston and the walls of the cylinder lil. Any desired number of piston rings may be employed, and in the construction illustrated by way of example, I have provided a piston ring 25 arranged in a groove formed in the upper portion of the piston, and another piston ring 21 arranged in a groove formed in the head I8 of the piston. The piston rings A25 and 21 are formed in segments and suitable means, not shown, are employed in the piston grooves to urge the piston rings 25 and 21 out- Wardly into engagement with the cylinder. y

'Ihe compressor shown is of the two-stage type, and for this purpose the piston II is provided with a portion 3u of smaller diameter than the upper end thereof, thus forming with the cylinder I a space 3i in which the second stage of compression is effected. In order to seal this space, the cylinder is provided with a downwardly extending s'xirt portion 32 in which is arranged a plurality of annular members 33, 34 and 35 of angle shaped cross section which are formed to intert in such a manner as to provide grooves for a plurality of piston rings 31. These rings are urged inwardly toward the wall of the piston II by suitable spring members 38 of any desired construction. 39 represents a collar having a screw threaded engagement with the lower end of the skirt 32 for pressing the annular members into contact with each other. The piston rings 31 are also formed of carbon or other material which does not require a lubricant. A piston of any other suitable or desired construction may be employed.

The cylinder I0 has a head which is tightly secured thereto. This cylinder head in the construction shown by way of example comprises a substantially disc-like body portion 45 adapted to fit against the upper end of the cylinder I0 and having an annular flange 4I extending upwardly from the peripheral portion of the body 40 of 'the head. The cylinder head also has a transversely or diametrically extending wall 42 which is preferably formed integral with the portion 40 and flange 4I of the piston head, and which divides theA space within the flange into two compartments. 43 represents a disc or circular plate, the edges of which are secured to the upper edge of the ange 4I and which also has a sealed lconnection withthe upright diametric wall 42 of the cylinder head. This cover or disc 43 may be secured in place on the cylinder head by means of bolts 44 which also serve to secure the cylinder head to the upper end of the cylinder.

The construction described forms two separate spaces or compartments 46 and 41 within the cylinder head, the space 4B being connected with the interior of the cylinder by means of a low pressure or suction valve 48 suitably mounted in the cylinder head to open when the piston II produces suction within the cylinder I0. The other space 41 in the cylinder head is connected with the cylinder by means of a low pressure discharge valve 49 through which the gas passes after the first stage of compression. A cylinder head and valve arrangement of any other suitable or desired type may be provided.

Suitable means are provided for enclosing the cylinder in a housing forming a container or dome forming an evaporator for a volatile liquid refrigerant which is vaporized by heat from the cylinder IIJ and other parts of the compressor, and by heat transmitted thereto from' the fermentation gas. In the construction shown for this purpose, the cylinder I0 is provided with a radially outwardly extending wall or flange 52 and a suitable housing or dome is secured to the peripheral portion of the flange 52. This housing or dome may be of any suitable or desired construction, and as illustrated includes a ring 53 formed to seat tightly on the ange 52. This ring has an inner wall 54 of the dome or housing secured thereto and an outer housing wall or dome 55 also secured to the ring in spaced relation to the inner wall 54. The space between the two walls is filled with suitable heat insulating material 56. The housing or dome, consequently, encloses the entire cylinder and all of the parts attached thereto above the flange 52. This dome forms an air-tight closure about the cylinder and is provided near the lower portion thereof with an inlet tube 58 for liquid refrigerant, and in the upper portion thereof, the dome is provided with a discharge tube 59 for volatiliZed refrigerant. As shown in Fig. '1, the pipes 58 and 58 are connected to a suitable refrigerating unit 6I) which includes a compressor and other instrumentalities (not shown), for liquefying vaporized refrigerant entering the refrigerating unit through the passage 59. Any suitable refrigerant may be employed, and the refrigerating unit GII may be a large refrigerating machine or ammonia compressor which also supplies liqmaestros 'uid fammoniafto other vapparatus lortevaporating #cil'sg or it may beL alseparate unit Vsupplying only fthecevaporatorenclosing the cylinderfll). "The frefrigerantemaylibeselected tol maintain-any defsiredlowtemperature'cfaboutthe A cylinder i it ,Y and 'to facilitate 'the transfer f df heat lfrom the interior "f the lcylinder 1li e* to :the refrigerant suriroun'di-ngf-the=cylinder,f the=walls of the cylinder unay belprovided with lradiating nsf62 oany desired typej't'hose shownl being integrally Vfor-med l'wil'kl'r'fthe cylinder 10. VThese "fins may, -if desired, be-'of spiralformso that any Igas-bubbles 4fforrned `between @the 'ns resulting from evaporation Iof "theflre'frigerant, will tend "to 'cw `upwardly along 'the spiral fins Vand be discharged therefrom for E:return Tto rthe llrefrigerating unit through, the

pipe'g. X

7-Tlsieflower 'end off thecylinder f Alis provided 'below the ange Zfwith `another' 'ange 64. The rspaceibetween'l the rtwo flanges is divided by means of two pairs of upright spacedw'alls'65 and 66 i-r'itotwomain compartments or chambers` 6-1 yand 68,fthesefchambers 'beingencl'osed by a periph- 'era'l annular upright wallBB, Fig. 6. The spaces between the fpairs of Iupright wallsff65 and GG Iforrrrpassages-or"smallerfchambers 1D and 1|.

"Thefperipheral fwallf'Sabout the chamber l61 '-is` 1vprovided at---one vside-fthereof witha threaded opening '1-3Ito 'Which-an 'inlet pipe "1d -for gas to becompressedisconnected by-means of a coup'ling'sleeve"'!5i. Attheotherside of the peripheral l*wall 69 a similar threaded opening 15 is @provided awhich leadsntothe chamber 68 'and lli-nto-fwhich-afthreaded plug 11 nts, and this plug =closesfvthefthreaded opening15 and may support x'aftemperature responsive member 13, by `means *of y*which'thevternperature of thegas in' the cham- 'berf' may be determined.

"Thechamber "61 at the y'lower part'of the cylinfderof thecompressor `is connected with the low fpressure 'suction chamber or space l5 4in `the A'cylinderhead by means of a seriespf-tubes or *conduits which'are'arranged in thespace between the inner wall-'5K3 of the insulating dome andthe fcylinder i0. Irrthe'particumr construction i1lus- "-'trate'd uin Figs. '3 and 5,r a `plurality of ytubes'l) isfshownf-Tforthis purpose, the'lowerends of these tubes-being suitably connectedwith the `passage *61 by suitable coupling-means ill. The Iupper @ends of the 'tubes 1180 `are connected by similar l coup1ir1g means 5S-2 with a series df `outwardly 'rf'extending hollow/projections "B3 of the cylinder hea'd. *These projectionsl Whichare bestshown lvin 1Figs. YL3 and 4 form continuations of'the"charn fiber 462and are provided with apertures in theA l"lower wallsfth'ereof which are threadedto coop- #f'eratewith the coupling-members 82. v'The tubes 8l) are made of a metal having good 'heat conductiv'iity'rand'are'preferably pro-vided on their outer surfaces with .heat radiating .ins..85. Eight of these tubes L80 Aare 4shown in the construction rillustrated, butit will be obvious that any desired number of tubes of thisltype'mayfbe provided. Consequently,..thefermentation gases to be compressed enter "fromthe tube "14 into the lower 'ichamber 61, see Figs. and 6, and pass `eupwardlysthrough the heat -exchange Vtubes 80 :Tinto the'1ow...pressure or-Suction chamber 46 Vin Ethe cylinder head. `.During Athispassage ofthe .gas through these tubes, -the outer surfaces of fwhich are `exposed to the refrigerant, the *gas is freceivedginfthe chamberllt` of "the cylinder head 'lata low temperature, Yand 'then `passes Athrough the suction tor inlet v.valve Vl4'3.'izlto1the upper-portion of the cylinder ID during the downward movementff the .piston Il. .Upon'ith'eJ returns.. or nupward fstrolref of -this piston, :inthe gas itis compressed l and discharged through #the vvalve w49 into the lcylindery fhead-1chamberI4-1. This .chamlber isrprovidedwvithhollow lateral projectionsrl, which may be` similar "in-construction to theprojections'lswhich connect withfrthe chamber A'146. 1I-ffhese projections :of the :cylinder lheadxare .nonnected by `Imeans :fof wheat `f-exchang'e tubes '88, '-which lfmay be similar"inconstructi'on to fthe tubes 8`,fv.rith'1the -lowerffchamber 66. Thegas 'is,-=o'ficourse, heated: during fthe compression rin lth'eeupper part dfthefcylinderf IB and bypassing through the -heatA exchange tubes 88 vwhich are immersed :in the refrigerantfthe temperaturewof this Igas `again lowered .so *that the same .fis ready lto' enter into lthe second stage lof'compression.

The lower chamber E8 is connected fwithlthe lower portion of the cylinder it() ibyun'ean's f1 oflan inlet or vsuction valve r-SIJ whichi'islarranged :between the chamber L68 with* the :space 3"6 between the-piston l l'andlthe'wall oftheacylinder t0. 'aConseQuently, during the-up stroke 'ofilthezpiston Il, gas lwhich'has been compressedfin :the .upper part ofthe cylinder-is admitted through' the va'lve90 finto the spacewlll, 'and 'upon the Adown 'stroke ofthe piston this compressed fgaspassesfthrough -adischargelvalve 9|, fFig.16,'into'the passage 1f! formed between the upright wallst5. Therouter end of this passage :is :closed by rmeans :of a -plug'92- .Thepassage 1| isvconnectedby means of `one Aor rmore heat exchange 4tubes-93, two suchutubes `being shown in .the construction illustrated. These tubes are of inverted U-sh'ape and are preferably also provided -With'heat radiating ns $4. These'tubessare connected `to receive comlpresse'dgasfromthe chamber 1|, and these tubes Vextend along one side'of the cylinder Yl-, then Fover the top of--the cylinder head'andfthere down along-the other side of the cylinder. The comfpressed gas'from these tubes is dischargedinto the chamber `10. This chamber has a threaded opening -in Which `is arranged a -suitabl'e pipe lcoupling memberfcon'nect'ed to a'discharge pipe 96 Ithrough which the compressed gas is dischargedafter havinglbeen chilled to. a low tem- .perature by` passing 'through the tubes :g3 `from .thechamber IH to thechamber 10.

By means'of the construction described, the fermentation gas can'readilybe 4.kept below the :temperature at which the aroma or flavor imparting Yingredients ofthe gas are-destroyed. The gas :is not only chilled -while passing throughthe heatzexchange `tubesflf,f 88 andffitpbut also While :inthe cylinder-since the refrigerant surround- .ing the cylinderkeeps the-walls of the cylinder'at Alow temperatures. 'The refrigerant also chills 4the larger` chambers 61 and' 6B-by being in con- :tact withthe-flange 52 which forms the upper Wall :of .these chambers. The `smaller chambers or ,passages -10-an-d `:'L-I :are also chilled 'in' a similar manner. The construction' described hasftherad- Vantage.` thatthe cooling pipes 88,88 and 93 are .completely .surrounded by refrigerant and the rlnslsecured to these tubes add greatly in dissipating heat '.from 'the tubes into the' refrigerant. y:By means "of the heat-responsive device 1.8,"the temperature ofthe lgas can be `observed andthe srefrigeratingcompressor regulated so as vtomain- `-tainthen'ecessary.low temperatures ofthe gas. 91,I 1lig.wf.5,r represents bolts n'conne'cting the 'lower dangeifoffthe .cylinder with' the upper ienelsw' the guides I4 for the crosshead I2.

By the use of a volatile liquid refrigerant about the housing or cylinder of the compressor and about the tubes which conduct the fermentation gas to and from the compressor, much lower temperatures of ,the fermentation gas and the compressor can be obtained, since the liquid refrigerant becomes gasied or vaporized by heat given off by the fermentation gas through the tubes and cylinder housing Walls, which Vapor moves rapidly out of contact with the surfaces to be cooled and flows to the top of the dome, from which it is withdrawn by the refrigerator unit. Consequently the surfaces to be cooled are substantially continuously in contact with low pressure liquid refrigerant, so that very efcient and rapid cooling of these surfaces results, whereby a rise in temperature such as will change the volatiles in the fermentation gas can be readily prevented.

By using rings which require no liquid lubricant, the fermentation gases are in no way adversely affected by the compression of the same and the gas may consequently be compressed while dry.

Various changes in the details, materials and arrangements of parts, which have been herein described and illustrated in order to explain thenature of the invention, may be made by those skilled in the art within the principle and scope of the invention, as expressed in the appended claims.

I claim as my invention:

1. Apparatus for low temperature compression of fermentation gas, including a cylinder in which the gas may be compressed, a cylinder head forming a compartment for gas to be compressed and-a compartment for compressed gas, said cylinder head having lateral extensions which project beyond the side walls of the cylinder and which are hollow and form lateral extensions of said compartments, a pair of annular flanges extending Y radially from the lower portion of said cylinder and integrally connected at their outer ends with a peripheral wall to forman enclosed space between said flanges, upright walls dividing said space between said flanges into a plurality of compartments, a plurality of tubes each connecting a compartment located between said flanges with a compartment of said cylinder head, an evaporator extending about said cylinder and said tubes, a refrigeration unit for supplying liquid refrigerant to said evaporator and for withdrawing refrigerant vapors from said evaporator, a

' conduit for admitting gas to becompressed to one of said compartments between said flanges, and a conduit connecting with another of said compartments between said flanges for the discharge of compressed fermentation gas from said apparatus, whereby incoming fermentation gas passes upwardly through tubes in heat exchange relation to said refrigerant from a compartment between said anges to said cylinder head, and compressed gas passes downwardly from said cylinder head to another of said compartments arranged between said flanges.

2. Apparatus for low temperature compression of fermentation gas, including a cylinder in which the gas may be compressed, a cylinder head forming a compartment for gas to be compressed and a compartment for compressed gas, said cylinder head having lateral extensions which project beyond the side walls of the cylinder and which are hollow and have the spaces enclosed thereby connected with said compartments, a hollow annular outwardly extending part formed integral with the lower portion of said cylinder and extending about the same, upright Walls in said hollow projection for dividing the space within said projection into separate compartments, an evaporator extending about said cylinder and having the lower end thereof secured to said annular projection, a tube for conducting gas from a compartment of said lower projection into said compartment in said cylinder head for gas to be compressed and extending through said evaporator, another tube connecting the other compartment of said cylinder head with another compartment of said annular projection, and extending through said evaporator, for conducting compressed gas from said cylinder head to said annular projection, said tubes being connected at the upper ends to the extensions of said cylinder head, and a refrigeration unit for supplying liquid refrigerant to said evaporator and for withdrawing vaporized refrigerant from the upper portion of said evaporator.

3. Apparatus for low temperature compression of fermentation gas, including a cylinder in which the gas may be compressed, a cylinder head having a compartment therein for gas to be compressed and a compartment for compressed gas, suction and discharge valves in said cylinder head for admitting to said cylinder and discharging therefrom fermentation gas of the first stage of compression, a hollow annular projection extending outwardly from the lower portion of said cylinder, upright walls dividing said projection into a plurality of compartments, one of said compartments having an inlet valve and another compartment having a discharge valve for the second stage of compression of the fermentation gas, and a plurality of tubes connecting the chambers of the annular projection with said cylinder head and spaced from said cylinder, an evaporator mounted on said annular projection and surrounding said cylinder and said tubes, and a refrigeration unit for delivering liquid refrigerant to said evaporator and for removing vaporized refrigerant from said evaporator.

4. Apparatus according to claim 3 in which said hollow annular projection is divided into four chambers, one of which receives gas to be compressed for passage through some of said tubes to said cylinder head, another compartment receiving compressed gas from said cylinder head through some of said tubes for discharge to the second stage of compression, a third compartment receiving gas compressed during the second stage of compression, a tube extending from said third compartment into a fourth compartment, said tube extending through said evaporator, and a conduit for conducting compressed gas from said fourth compartment.

GRANT E. HOCKENS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 144,390 Day Nov. 11, 1873 1,443,135 Lafferty Jan. 28, 1923 1,478,162 Anderson Dec. 18, 1923 1,519,932 Reich Dec. 16, 1924 1,949,812 Read Mar. 6, 1934 1,974,791 Belt Sept. 25, 1934 2,160,187 Winkler May 30, 1939 2,362,984 Boshko Nov. 21, 1944 

